形容詞 conscientious:

1. characterized by extreme care and great effort
   同義詞：painstaking, scrupulous
2. guided by or in accordance with conscience or sense of right and wrong

1. The janitor is very conscientious.
   那個管理員很認真。
2. He's changed into a conscientious worker.
   他已成為一個工作認真的人了。
3. We should be conscientious to our work.
   我們應該對工作負責。
4. She is a conscientious teacher.
   她是一個有責任心的教師。

con.sci.en.tious

adj.（形容詞）
Guided by or in accordance with the dictates of conscience; principled:
本著良心的：由良心指引或與良心一致的；有原則的：
例句：
a conscientious decision to speak out about injustice.
本著良心決定說出不義之事

Thorough and assiduous:
負責的：周全的和勤勉的：
例句：
a conscientious worker; a conscientious effort to comply with the regulations.
謹慎的員工；全力與規(guī)定配合

來源：
Obsolete French conscientieux
已廢法語 conscientieux
from Medieval Latin cônscientiôsus
源自 中世紀拉丁語 cônscientiôsus
from Latin cônscientia [conscience] * see conscience
源自 拉丁語 cônscientia [良心] *參見 conscience

【引伸】
con.scien.tiously
adv.（副詞）
con.scien.tiousness
n.（名詞）